For those of you who followed TXSharon's diaries on the Spring Creek cattle deaths, there has finally been (some) resolution to the story:
The "stuff" killed the cows.
There's still no toxicology report being released, but it appears they acknowledge it was something from the fracturing process:
Schlumberger has added additional secondary containment materials around bulk hydraulic fracturing chemical storage and has increased the policing of chemical storage and transfer areas during operations
This is pretty much what was expected, but as the story fell off (as close as it came) the front page, people interested in the original story might be interested.
Without a toxicology report released to the public, we'll never know whether it was some exotic fracturing fluid ingredient that killed the cattle, or something a simple as antifreeze.